Almost all of them have European surnames, but only ~20% of them have a European ancestor. If you are white, chances are good one of your ancestors came from France, or used a French surname to fool the authorities.
1 AC, or alternating current means the electrical current is alternating directions in a repetitive pattern.  AC is created by generators in power plants, and other sources. This AC current is delivered to our homes and businesses by the power lines we see everywhere.
Alternating current. Direct current (DC) circuits involve current flowing in one direction. In alternating current (AC) circuits, instead of a constant voltage supplied by a battery, the voltage oscillates in a sine wave pattern, varying with time as: In a household circuit, the frequency is 60 Hz. The angular frequency is related to the frequency, f, by: Vo represents the maximum voltage, which in a household circuit in North America is about 170 volts. We talk of a household voltage of 120 volts, though; this number is a kind of average value of the voltage.